Thread: Kind of a Drag

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Ignition was changed a couple years ago with a fresh MSD distributor and a MSD Street fire ignition box. Distributor mechanical advance changed with a Moroso recurve kit. Vacuum advance is adjustable. No ignition in distributor just a connection to the hall effects switch. Recently I changed plugs, new Taylor 8mm wires, cap, rotor, coil, no resistance center electrode, Rebuilt the carburetor,, changed gaskets for the base and nitrous plate, checked intake and exhaust bolts. I did not change the jetting or springs in the carb as it was fine before in fact it's at a sweet spot and checked out on the dyno. Static timing is set to 10.5 Dyno says sweet spot is 11 BTDC.
No changes were made to the adjustments except fuel filter which is now a little billet canister with one of those old style q-jet bronze filters in it. I didn't want a fuel leak on the headers. I also re adjusted the valve lash. Vacuum advance is set in the middle.

So this phenomenon has happened 3 times going from Kansas City to Gardner Kansas on I-35. By the time I get to Overland Park it starts popping just little farts. Then it crescendos to major blasts sounding like shotgun fires scaring to crap out of random drivers. Even at cruising and especially at any acceleration. At my destination even idling in park it still bangs em out only last time it was the left muffler instead of the right that was doing most of the singing. So, i start the return trip and its blasting down the freeway, bang bang bang. Then it retires to Pop Pop pop, then occasional pop, then nothing. By the time I park it's back to normal. Same trips for the same reasons. I visit my ex-pastors house but it's only to work on his cars honest! That's why I think the car got demon possessed, like Christine.
I'm sure the pops are centered in the mufflers. I do notice a slight lope in the engine but may be unrelated. The car is cold starting out both ways then gets warm. So, i'm not sure about the gaskets but at this point, I don't have a clue.
Now, I plan to check everything ignition again, any slop that may be in the timing chain and do a compression test. It's all I can think of. Beyond that all I can think to do is pull the heads. Of all the years and training I had I never ran across a problem I couldn't figure out until now. I've got to fix it. It's our only ride now. Any help I could get would be appreciated. Especially before pulling the heads. We can't afford gasket replacement.

Originally Posted by Good Wrench

Ignition was changed a couple years ago with a fresh MSD distributor and a MSD Street fire ignition box. Recently I changed plugs, new Taylor 8mm wires, cap, rotor, coil, no resistance center electrode.

changed gaskets for the base and nitrous plate,

fuel filter which is now a little billet canister with one of those old style q-jet bronze filters in it.

MSD usually doesn't like solid conductor wires (no resistance).

Are you using nitrous?

Have you checked fuel filter for clog/pressure loss?